JP2005076964A - Heat pump hot water supplier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce thermal loss in a hot water tank, about a heat pump hot water supplier equipped with the hot water tank for storing hot water heated by a heat pump. <P>SOLUTION: As the heat pump hot water supplier is equipped with the heat pump 1 for heating water to be supplied, the hot water tank 21 for storing the hot water heated by the heat pump 1, a first hot water supply pipe for communicating a hot water supply port of the heat pump 1 with a top part of the hot water tank 21, a second hot water supply pipe for communicating a water supply source and a bottom part of the hot water tank, a water supply pump 23 for supplying water at the bottom part of the hot water tank 21 to the heat pump 1 and a hot water quantity adjusting means for adjusting hot water quantity to be equal to or more than a setting quantity by activating the heat pump 1 and the water supply pump 23 when detecting that hot water quantity in the hot water tank equal to or hotter than a setting temperature is less than the setting quantity, thermal loss at the hot water tank 21 can be reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat pump hot water supply apparatus, and more particularly, to a device provided with a hot water storage tank for storing hot water heated by a heat pump.

  As a conventional heat pump hot water supply device, the heat pump is operated at night when electric power is inexpensive, and the hot water supply is filled and stored in a hot water storage tank so as to cover hot water used during the day.

  Moreover, when heating feed water with a heat pump, if the outside air temperature changes, the operating efficiency of the heat pump may change, and the hot water temperature in the hot water storage tank may change. Therefore, a method has been proposed in which the compression capacity of the heat pump is adjusted in accordance with the outside air temperature to stabilize the hot water temperature against changes in the outside air temperature (see Patent Document 1).

  Further, the amount of hot water used generally varies depending on the outside air temperature. Therefore, according to the hot water storage system for storing a predetermined amount of hot water, for example, the amount of hot water is excessive in summer when the amount of use is relatively small, whereas the amount of hot water is insufficient in winter when the amount of use is large. According to the conventional hot water storage system, once the hot water runs out, a long time is required until a predetermined amount of hot water is boiled again. Therefore, in order to prevent running out of hot water, the capacity of the hot water storage tank is increased (for example, 300 to 450 L), stored at as high a temperature as possible (for example, 90 ° C.), and diluted with a large amount of water for use. .

JP 2001-255004 A

  However, when the hot water tank is increased in size, the installation space is increased and the strength of the installation floor is required. Therefore, it is difficult to install in a narrow space such as an apartment or a condominium veranda, and further, there is a problem that much labor and cost are required for transporting the apparatus.

  Therefore, a heat pump and a hot water tank are used together. Immediately after the start of hot water supply, hot water is stored using hot water stored in the hot water tank. During that time, the heat pump is operated, and when the heating capacity of the heat pump is stabilized, hot water is supplied from the hot water tank. A method of stopping and switching to direct hot water supply by a heat pump is conceivable. According to this, there is an advantage that the amount of hot water stored in the hot water tank can be greatly reduced and the hot water tank can be downsized.

  However, even in a hot water supply apparatus equipped with such a miniaturized hot water storage tank, since a predetermined amount of hot water having a temperature higher than the surroundings is stored, a loss of heat radiated from the wall surface of the hot water storage tank is unavoidable. Therefore, depending on the outside air temperature, heat loss is increased, resulting in energy loss, so there is room for improvement in heat loss in the hot water tank.

  An object of the present invention is to reduce heat loss in a hot water tank.

  The heat pump hot water supply apparatus of the present invention includes a heat pump for heating water, a hot water storage tank for storing hot water heated by the heat pump, a first hot water supply pipe communicating with the hot water outlet of the heat pump and the top of the hot water storage tank, and a hot water storage tank A second hot-water pipe communicating with the top of the hot water supply port, a water supply pipe communicating with the water supply source and the bottom of the hot water tank, a water supply pump supplying water to the heat pump from the bottom of the hot water tank, and a set temperature of the hot water tank or higher It is characterized by comprising a hot water amount adjusting means for detecting the amount of hot water and adjusting the hot water amount to be equal to or higher than the set amount by operating the heat pump and the feed water pump when the detected value is less than the set amount. To do.

  According to such a configuration, for example, the heat loss due to excessive hot water storage can be reduced by setting an appropriate amount of hot water (hot water storage amount) in the hot water storage tank according to the outside air temperature or the like. That is, in summer when the outside air temperature is high, the amount of hot water used is small and the temperature drop in the hot water tank is slow, so the amount of hot water stored can be set small. On the contrary, in winter when the outside air temperature is low, the amount of hot water used is large and the temperature in the hot water tank is rapidly decreasing, so the amount of hot water stored is set large.

  In this case, it is preferable to connect the first and second hot water supply pipes. According to this, since the hot water can be directly supplied from the heat pump after the heat pump is stably operated, even if the hot water storage tank is downsized, the hot water does not run out. Moreover, since the hot water temperature can be lowered instead of reducing the amount of hot water in the hot water storage tank, the heating efficiency by the heat pump is improved.

  Specifically, a heat pump that heats the water supply, a hot water tank that stores hot water heated by the heat pump, a first hot water pipe that communicates the hot water outlet of the heat pump and the top of the hot water tank, and the first hot water pipe A second hot water pipe that communicates with the hot water outlet, a water pipe that communicates between the water source and the bottom of the hot water tank, a water pump that supplies water to the heat pump from the bottom of the hot water tank, and a hot water amount that exceeds the set temperature of the hot water tank When the detected value is less than the set amount, the heat pump and the water supply pump are operated to adjust the hot water amount so that the amount of hot water is equal to or greater than the set amount, and the opening of the hot water inlet is detected. And a control means for starting water supply to the heat pump after the heating capacity of the heat pump is stabilized.

  Further, it is preferable that the hot water amount adjusting means detects at least one of an outside air temperature and a feed water temperature and variably sets the set amount based on the detected temperature. According to this, by determining the optimum amount of hot water for the detected temperature in advance, it is possible to appropriately change the amount of hot water according to the detected temperature and maintain the state of the optimum amount of hot water. In addition, supply water temperature, such as tap water, is generally more preferable because it has less fluctuation and higher reliability than the outside air temperature.

  In addition, the hot water storage tank is provided with a plurality of temperature sensors in the height direction, and detects the amount of hot water equal to or higher than the set temperature based on the detected temperature detected directly or indirectly by the temperature sensor. That is, in the hot water tank, hot water and water form layers respectively up and down and are stored in full, so the amount of water changes as the amount of hot water changes. Therefore, the amount of hot water equal to or higher than the set temperature can be detected by detecting the temperature at a plurality of locations in the height direction.

  According to the present invention, heat loss in the hot water tank can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a heat pump water heater to which the present invention is applied. As shown in the figure, the heat pump hot water supply apparatus includes a heat pump refrigerant circuit 1, a hot water supply circuit 3, and an operation control means 5. The heat pump refrigerant circuit 1 employs a two-cycle system consisting of two refrigerant circuits, and includes a first closed circuit in which a compressor 7a, a gas cooler 9a, a pressure reducing device 11a, and an evaporator 13a are sequentially connected in series, a compressor 7b, and a gas cooler. 9b, a decompression device 11b, and a second closed circuit in which the evaporator 13b is directly connected sequentially, and refrigerant is sealed in each circuit.

  The compressors 7a and 7b are capable of capacity control, and are operated with a large capacity when supplying a large amount of hot water. Here, the compressors 7a and 7b are rotated from low speed (for example, 2000 rotations / minute) to high speed (for example, 8000 rotations / minute) by PWM control, voltage control (for example, PAM control) and combination control thereof. Can be controlled. The water-refrigerant heat exchanger 15 includes a refrigerant side heat transfer tube and a water supply side heat transfer tube, and the gas coolers 9a and 9b function as refrigerant side heat transfer tubes 9a and 9b, respectively. Heat exchange is performed between 9b and the water supply side heat transfer tubes 9c and 9d. The evaporators 13a and 13b are air-refrigerant heat exchangers that exchange heat between air and refrigerant.

  The defrosting solenoid valves 17a and 17b include an electromagnetic coil and an opening / closing valve that is opened only when the electromagnetic coil is energized, and bypasses the outlet side of the compressors 7a and 7b and the inlet side of the evaporators 13a and 13b. When the evaporators 13a and 13b are frosted, the open / close valve is opened, and the high-temperature and high-pressure refrigerant gas discharged from the compressors 7a and 7b is guided to the evaporators 13a and 13b so as to defrost. It has become.

  The hot water supply circuit 3 includes a hot water storage circuit, a direct hot water supply circuit, a tank hot water supply circuit, a tank remedy circuit, a bath hot water filling circuit, and a bath remedy circuit. The hot water storage circuit and the tank tracking circuit are the hot water storage tank 21, pipe 25, tank circulation pump 23, pipes 27 and 29, water supply side heat transfer pipes 9c and 9d, pipe 31, heat exchange side flow rate adjustment valve 33, pipe 35, tank side. The flow adjustment valve 37 and the pipe 39 are configured in a closed circuit, and the pipes 25 and 39 are connected to the bottom and top of the hot water storage tank 21, respectively. That is, the water forcibly extracted from the bottom of the hot water storage tank 21 by the tank circulation pump 23 is led to the water-refrigerant heat exchanger 15 to be heat exchanged and heated, and then again from the top of the hot water storage tank 21. It comes to be supplied.

  In the direct hot water supply circuit, the water supply port 41 is connected to the water proportional valve 45 via a pipe 47 provided with a pressure reducing valve 43, and then a pipe 49, a water supply check valve 51, a pipe 29, a water supply side heat transfer pipe 9c, and 9d, piping 31, heat exchange side flow rate adjustment valve 33, piping 35, 53, 55, and hot water supply port 57 are connected in series in this order. As a result, the water supplied from the water supply port is guided to the water-refrigerant heat exchanger 15 to be heat-exchanged, and after being heated, hot water is supplied from the hot water supply port.

  In the tank hot water supply circuit, a water supply port 41 is connected to a water proportional valve 45 via a pipe 47 provided with a pressure reducing valve 43, and then a pipe 49, a hot water storage tank 21, a pipe 39, a tank side flow rate adjusting valve 37, a pipe. 53 and 55 and the hot-water supply port 57 are connected in series in this order. That is, since the hot water storage tank 21 is full of hot water, when water having a predetermined water pressure is introduced into the hot water storage tank 21 from the bottom of the hot water storage tank 21, the pressure in the hot water storage tank 21 increases. Accordingly, hot water is discharged from the top of the hot water storage tank 21 and supplied from the hot water supply port 57. In this circuit, the pipe 39 used when hot water is supplied from the hot water storage tank 21 is also commonly used when hot water is stored in the hot water storage tank 21 in the hot water storage circuit. For example, the pipe 39 is separated into two, You may make it make piping communicate.

  In the hot water bathing circuit, a water supply port 41 is connected to a water proportional valve 45 through a pipe 47 provided with a pressure reducing valve 43, and then a pipe 49, a water supply check valve 51, a pipe 29, and a water supply side heat transfer pipe 9c. And 9d, piping 31, heat exchange side flow rate adjustment valve 33, piping 35, 53, pouring solenoid valve 56, piping 58, bath water amount sensor 59, piping 61, bath water heater 63, and bathtub 65 are connected in series in this order. Is done. As a result, the water supplied from the water supply port is guided to the water-refrigerant heat exchanger 15 for heat exchange, and after being heated, hot water is supplied into the bathtub. In addition, during hot water bathing, hot water can be supplied from the hot water storage tank 21 within the range where the hot water storage amount of the hot water storage tank 21 does not become less than the preset minimum hot water storage amount, as well as direct hot water supply by the hot water bathing circuit.

  In the bath memorial circuit, the water connection port of the bathtub 65 is connected to the bath circulation pump 71 via a pipe 69 provided with a bath outlet metal fitting 67, and then a pipe 73, a bath water heat transfer pipe 77, and pipes 81 and 61. , Bath water heater 63 and bathtub 65 are connected in series in this order. That is, in the bath memory circuit, the bath circulation pump 71 forcibly extracts the hot water in the bathtub 65 and then returns it to the bathtub 65 again through the bath heat exchanger 75. The bath heat exchanger 75 guides part of the hot water heated by the water-refrigerant heat exchanger 15 to the hot water heat transfer tube 79 and exchanges heat with the bath water heat transfer tube 77. .

  The water supply port of the hot water heat transfer pipe 79 in the bath heat exchanger 75 is connected to the hot water supply port of the water-refrigerant heat exchanger 15 through the pipes 31, 35, 83, and the pipe 83 includes a water opening / closing valve 85. . The water on / off valve 85 is closed except during bath chase to prevent heat leakage from the water-refrigerant heat exchanger 15 to the bath heat exchanger 75. The pipe 87 formed by passing the pipe 81 and the pipe 73 is provided with a bath check valve 89 so that priming water is supplied to the bath circulation pump 71 when hot water is supplied to the bath. In addition, the pipe 91 formed by branching the water supply side pipe 39 of the hot water storage tank 21 is provided with a relief valve 93, so that it operates when the hot water pressure in the hot water storage tank 21 rises to a predetermined level or more to provide pressure protection. It is like that.

  The hot water storage tank 21 is constituted by a small tank having a cylindrical shape which is formed vertically and has a small capacity of about 1/3 to 1/5 of the hot water storage tank in the conventional hot water storage system. In the hot water storage tank 21, water and hot water are stored separately in the vertical direction due to the difference in specific gravity. That is, the supplied water is stored in the lower layer of the tank, and hot water obtained by heating the lower layer water is stored in the upper layer. A plurality of temperature detection thermistors and the like are attached in the hot water storage tank 21 in the height direction, and the temperature distribution in the hot water storage tank 21 is detected directly or indirectly to detect the amount of hot water stored above the set temperature. ing. Here, the temperature detection thermistor may be arranged in the hot water storage tank 21 so as to directly detect the temperature. However, in terms of assemblability and serviceability, the temperature detection thermistor is arranged outside the side wall and indirectly detects the temperature. You may make it do.

  The operation control means 5 receives detection signals from a temperature sensor that detects the temperature state of each part, a pressure sensor that detects the discharge pressure of the compressors 7a and 7b, a water level sensor that detects the water level in the bathtub 65, and the like. Each device is controlled based on the above. For example, the operation setting of the kitchen remote controller 101 and the bath remote controller 103 is used to stop the operation of the heat pump refrigerant circuit 1, control the rotation speed of the compressors 7 a and 7 b, and stop the operation of the tank circulation pump 23 and the bath circulation pump 71. By controlling the water proportional valve 45, the heat exchange side flow rate adjustment valve 33, the tank side flow rate adjustment valve 37, the hot water solenoid valve 56, the water on / off valve 85, etc. in a well-known manner, tank hot water storage operation, direct hot water supply operation, tank A hot water supply operation, a tank chasing operation, a bath hot water driving operation, and a bath chasing operation are respectively switched and controlled. The operation control means 5 controls the operation of the compressors 7a and 7b at a predetermined high speed in order to shorten the heating start-up time immediately after the heat pump refrigerant circuit 1 is started.

  Further, the operation control means 5 has a function of a hot water storage operation every time so as to perform a tank hot water storage operation after the tank hot water supply operation and stop the operation after storing the hot water storage amount in the hot water storage tank 21 to a set amount or more. Yes. That is, when the amount of hot water stored in the hot water storage tank 21 is equal to or higher than the set temperature is detected by the above-described method and the hot water storage amount is less than the predetermined amount, the heat pump refrigerant circuit 1 and the tank circulation pump 23 are operated. The amount of hot water stored is adjusted to a set amount or more by returning the water extracted from the top to the top after heat exchange.

  In this case, the set amount of the hot water storage is set to be variable based on the detected temperature by detecting at least one of the outside air temperature and the feed water temperature. For example, the amount of stored hot water is reduced in summer when the outside air temperature is high, and the amount of stored hot water is increased in winter when the outside air temperature is low. In other words, the optimum amount of hot water is set by calculating the detected value such as the outside air temperature with a function stored in advance, and as a result, the hot water storage tank 21 has a minimum necessary amount that is not excessive or insufficient for the use conditions. A limited amount of hot water is stored. The set amount of hot water may be controlled in several stages according to the season, for example, 50 L in summer, 70 L in spring and autumn, and 100 L in winter, instead of the above method. Further, the required amount of hot water may be stored and learned and controlled.

  FIG. 2 is a schematic diagram illustrating an example of the water-refrigerant heat exchanger 15 in the present embodiment. As shown in the figure, the water-refrigerant heat exchanger 15 is a heat exchanger dedicated to hot water supply separated from the bath heat exchanger 75, and includes two refrigerant heat transfer tubes 9a and 9b, two water supply heat transfer tubes 2c, The refrigerant heat transfer tubes 9a and 9b and the feed water heat transfer tubes 9e and 9f are alternately brought into a cylindrical shape. Although not shown, in the present embodiment, the water-refrigerant heat exchanger 15 may be wound around the outer peripheral wall of the cylindrical hot water storage tank 21 or arranged concentrically. According to this, heat dissipation from the hot water storage tank 21 can be suppressed, and heat loss can be reduced. Moreover, although the water supply heat exchanger tube of this embodiment is branched into two in order to reduce internal pressure loss, it is not restricted to this.

  FIG. 3 is a schematic diagram showing an example of the bath heat exchanger 75 in the present embodiment, where (a) shows a cross-sectional view from the side, and (b) shows a cross-sectional view from the front. As shown in the figure, the bath heat exchanger 75 has a double pipe structure in which a bath water heat transfer tube 77 having a hollow hollow section is inserted into a hot water heat transfer tube 79 made of a copper tube. The small diameter pipes 77a and 77b formed at both ends of the bath water heat transfer pipe 77 are airtightly joined from the outer peripheral side. Hot water heated by the water-refrigerant heat exchanger 15 is guided to the inside through a hot water pipe 79 a formed by drilling a side wall of one end of the hot water heat transfer pipe 79, and the hot water pipe 79 and the bath water heat transfer pipe 77. The bath water flows out to the outside through the hot water pipe 79b formed on the side wall at the other end, while the bath water is led into the bath water heat transfer pipe 77 through the small diameter pipe 77a at one end. In addition, it flows out to the outside through the small diameter pipe 77b at the other end. It is desirable that the bath water heat transfer tube 77 be formed in a concave-convex shape, a star shape, a multi-leaf tube or the like in order to increase the contact area with hot water. By taking a double tube structure in this way, the bath water heat transfer tube 77 is transferred on the entire outer periphery, and a bath heat exchanger 75 having a compact size and good heat transfer can be obtained.

  In other words, the conventional heat exchanger for bath remedy performs heat exchange between the refrigerant heat transfer tube of the heat pump and the bath water heat transfer tube, so that in the unlikely event that the inner tube is damaged, the high-pressure refrigerant enters the water circuit and the wash surface May contaminate hot water and kitchen hot water. For this reason, the double pipe structure is not adopted, and it is necessary to have a pipe structure in which the refrigerant pipe and the water pipe are made independent of each other. On the other hand, according to this embodiment, since the bath heat exchanger 20 is separated from the water-refrigerant heat exchanger 15 and is configured to exchange heat with the heated circulating water, a double pipe structure can be taken. it can.

  With the configuration as described above, when the hot water supply is started, the heat pump hot water supply apparatus of the present embodiment first supplies hot water from the hot water storage tank 21 in which a set amount of hot water is stored by the tank hot water storage operation. When the heating capacity of the heat pump refrigerant circuit 1 is stabilized, the operation is switched to the direct hot water supply operation, and the hot water boiled by the water-refrigerant heat exchanger 15 is controlled to be directly supplied from the hot water supply port. Furthermore, if necessary, the hot water in the bathtub 65 is chased by a bath heat exchanger 75 having a double pipe structure.

  Next, operation | movement of the heat pump hot-water supply apparatus of this embodiment is demonstrated. Initially, the operation | movement operation | movement at the time of installation of this apparatus is demonstrated using the flowchart of FIG.

  First, in step S101, the heat pump hot-water supply device is transported from the manufacturing location and installed in an installation location. In step S102, after the water supply fitting of the water supply port 41 is connected to a water supply source such as a water supply and the relief valve 93 is opened, when the main plug is opened, water supply is started from the water supply source, and the water is supplied to the pressure reducing valve. After the pressure is reduced to a constant pressure by 43, the hot water is stored in the hot water storage tank 21, the water-refrigerant heat exchanger 15, and each pipe. At the same time, air in the water cycle of the hot water supply device is expelled from the relief valve into the atmosphere. In this case, each device at the time of installation of the heat pump water heater is set to the following initial state. That is, the water proportional valve 45 is open on the hot water storage tank 21 side, the hot water supply port 57 side is closed, the heat exchange side flow rate adjustment valve 33, the tank side flow rate adjustment valve 37, and the water on / off valve 85 are all open, and the pouring solenoid valve 56 is closed. It is in the state.

  When the entire water cycle of the hot water supply apparatus is filled with water and water begins to flow out of the relief valve 93, it is determined in step S103 that the water supply has been completed, and the relief valve 93 is closed. Subsequently, in step S104, the power switch of the apparatus is turned on, the operation of the heat pump refrigerant circuit 1 and the hot water supply circuit 3 is started under the control of the operation control means 5, and the tank hot water storage operation is performed. That is, in the heat pump refrigerant circuit 1, the operation of the compressors 7a and 7b is started, and the gaseous refrigerant in the compressors 7a and 7b is compressed and heated to be a high-temperature and high-pressure refrigerant and sent to the water-refrigerant heat exchanger 15. . Thereby, in the water-refrigerant heat exchanger 15, the high temperature refrigerant flowing in the refrigerant side heat transfer tubes 9a and 9b and the water supply flowing in the water supply side heat transfer tubes 9c and 9d exchange heat, the refrigerant dissipates heat, Heated. The radiated refrigerant is depressurized by the decompression devices 11a and 11b, and then is expanded and evaporated by the evaporators 13a and 13b to be in a gas state, and returns to the compressors 7a and 7b again.

  On the other hand, when the operation of the tank circulation pump 23 is started, the water forcibly extracted from the bottom of the hot water storage tank 21 is the tank circulation pump 23, the water-refrigerant heat exchanger 15, and the heat exchange side flow rate adjustment valve 33. Then, the water is returned to the top of the hot water storage tank 21 via the tank side flow rate adjusting valve 37 in order. As a result, hot water heated by the water-refrigerant heat exchanger 15 is gradually stored in the upper part of the hot water storage tank 21, and among the temperature detection thermistors 110 attached in the height direction of the hot water storage tank 21, In order from the one installed at a higher position, the temperature above the set temperature is detected and the amount of hot water stored is detected.

  In step S105, when the hot water storage amount reaches the set amount and it is determined that the hot water storage is completed, the process proceeds to step S106, and the operation is stopped. Note that the amount of hot water storage can be easily determined from the inner diameter of the hot water storage tank if the tank height position detected by the temperature detection thermistor 110 is known. The method for detecting the amount of hot water storage is not limited to the temperature detection thermistor 110. For example, a flow rate sensor or the like may be provided in the hot water storage circuit to directly measure the flow rate. Further, the number of temperature detection thermistors may be increased, and the amount of hot water stored may be set finely including the daytime and night time zones in addition to the season.

  Next, the operation during hot water supply will be described with reference to the flowchart of FIG. When the faucet of the hot water supply port 41 is opened and hot water is supplied in step S111, the process proceeds to steps S112 and S113, and the direct hot water supply operation and the tank hot water supply operation are started simultaneously. That is, in the direct hot water supply operation, the operation control means 5 starts the compressors 7a and 7b to start the operation of the heat pump circuit 1, and allows water to flow directly through the hot water supply circuit to exchange heat. On the other hand, in the tank hot water supply operation, water is supplied to the tank hot water supply circuit to supply hot water in the hot water storage tank 21.

  Here, the heat pump refrigerant circuit 1 sends the high-temperature refrigerant compressed by the compressors 7a and 7b to the water-refrigerant heat exchanger 15, and the heating capacity of the water flowing through the water supply pipes 9c and 9d is increased with time. However, at the start of operation, the refrigerant sent to the water-refrigerant heat exchanger 15 does not reach a sufficiently high temperature and pressure, and the entire water-refrigerant heat exchanger 15 is cooled. The ability is not enough.

  Therefore, a tank hot water supply operation for supplying hot water from the hot water storage tank 21 is performed for a predetermined time immediately after the start of operation (about 1 to 2 minutes), and the operation control means 5 stabilizes the heating capacity of the heat pump refrigerant circuit 1 in step S114. It is detected whether or not the tank hot water supply operation is continued or stopped. If it is determined that the operation has been stopped, the process proceeds to step S115, where the tank hot water supply operation is stopped and the direct hot water supply operation is switched to only. As a method of determining the heating capacity of the heat pump refrigerant circuit 1, as shown in step S116, for example, temperature detection for detecting the temperature of hot water flowing out from the water supply side heat transfer tubes 9c and 9d in the water-refrigerant heat exchanger 15 It is determined whether or not the detection value detected by the thermistor 112 or the flow rate sensor 114 for detecting the flow rate of hot water flowing out of the heat transfer tube is equal to or greater than a predetermined value. Try to judge.

  As described above, since the hot water supply is transiently supplied from the hot water storage tank 21 at the start of operation and then the hot water heated by the water-refrigerant heat exchanger 15 is directly supplied, a two-system hot water supply method is employed. The heating delay at the start of operation is eliminated, and the capacity of the hot water storage tank 21 can be significantly reduced. The operation control means 5 stops the tank hot water supply operation when the remaining hot water amount in the hot water storage tank 21 becomes a predetermined value or less, and operates only with the direct hot water supply operation.

  When the hot water supply is completed and the faucet of the hot water supply port 57 is closed, if the tank hot water supply operation and the direct hot water supply operation are performed immediately after the hot water supply, both the tank hot water supply operation and the direct hot water supply operation are performed in steps S115 and S117. If the tank hot water supply operation is stopped and only the direct hot water supply operation is performed, the direct hot water supply operation is stopped in step S117.

  Next, the operation control means 5 stops the tank hot water supply operation and the direct hot water supply operation, and then starts the tank hot water storage operation in step S118. That is, a hot water storage amount equal to or higher than the set temperature is detected by a plurality of temperature detection thermistors 110 arranged in the hot water storage tank 21, and the hot water storage amount is determined in step S119. Here, when the amount of stored hot water is equal to or greater than the set amount, the process proceeds to step S120 and the operation is terminated. On the other hand, when the amount is less than the set amount, the tank circulation pump 23 is operated in addition to the heat pump refrigerant circuit 1, and the flow rate is adjusted so that the amount of stored hot water is equal to or greater than the set amount. Even after the hot water supply is stopped, if the hot water temperature and the amount of hot water in the hot water storage tank 21 are substantially equal to the preset values, the hot water storage is completed, and the hot water storage in the tank is determined. Do not drive.

  As described above, every time the operation control means 5 performs the tank hot water storage operation until the set amount of hot water storage set according to the outside air temperature, the feed water temperature, or the like is reached after the end of the operation. It has a hot water operation function. Therefore, a set temperature and a set amount of hot water are always stored in the hot water storage tank 21, so that a decrease in hot water temperature at the start of operation is eliminated and heat loss due to excessive hot water storage is reduced. Moreover, since it is not necessary to store hot water higher than necessary, the energy efficiency of the heat pump is improved.

  Furthermore, since it takes about 5 to 6 minutes for the heating capacity of the heat pump operation to reach a high temperature stable state, it is necessary to cover all of it with the amount of hot water in the hot water storage tank 21 until then. However, according to the present embodiment, since a two-cycle system in which two heat pump refrigerant circuits 1 are provided is adopted, the heating capacity is doubled, and the operation speed of the compressor is controlled at a higher speed than usual. By doing so, the predetermined time from the start of operation until reaching the high temperature stable state can be shortened to about 1-2 minutes. Thereby, direct hot water supply by a heat pump system can be realized, and the hot water storage tank 21 can be further miniaturized.

  Next, the hot water filling operation in the bath automatic operation will be described with reference to the flowchart of FIG. Note that description of operations similar to those in FIG. 5 is simplified. First, in step S121, when the bath automatic button is pressed, the timer 121 starts time measurement. Subsequently, when it is determined in step S123 that the set time has come, the process proceeds to steps S124 and S125, and the bath hot water supply operation and the tank hot water supply operation are performed simultaneously. In the bath hot water supply operation, hot water is supplied into the bath tub by the direct hot water supply operation described above. That is, for 1 to 2 minutes immediately after the start of the heat pump operation, the bath hot water supply operation and the tank hot water supply operation are performed simultaneously, and during that time, the temperature detection thermistor 112 and the flow rate sensor 114 detect the bath hot water supply amount and the hot water supply temperature. If it is determined in step S127 that the tank hot water supply operation is stopped, and if the tank hot water supply operation is stopped in step S129, only the bath hot water operation is performed. During the bath water supply operation, the bath hot water temperature and the amount of hot water in the bathtub are detected continuously or periodically, and the following control is performed by the operation control means 5.

  First, in step S131, the heat pump refrigerant circuit 1 controls the rotation speed and the feed water flow rate of the compressors 7a and 7b, and then in step 133, determines whether or not the bath hot water temperature is within the set temperature range. . If the temperature is within the set temperature range, the process proceeds to step S135. If the temperature is out of the range, the control in step 131 is repeated so that the temperature is within the range. Subsequently, in step S135, the hot water temperature and the hot water amount in the bathtub 65 are detected by the temperature detection thermistor 126 and the water level sensor 127, respectively, and are determined based on the detected values. When the hot water temperature and the hot water amount reach the set amount, the process proceeds to step S137, the bath hot water supply operation is stopped, and when the hot water temperature and the hot water amount do not reach the set amount, the hot water supply is continued.

  Next, the bath memorial operation in bath automatic operation will be described using the flowchart of FIG. First, when the bath automatic button is pressed in step S141, the hot water temperature and hot water amount in the bathtub 65 are detected by the temperature detection thermistor 126 and the water level sensor 127, and then in step S143, the detected hot water temperature and hot water amount are set. It is determined whether the value is within the range. If these detected values are within the set value range, the process proceeds to step S153 to omit the bath chase operation, and if outside the range, the process proceeds to step S145 to start the bath chase operation.

  During the bath memorial operation, the bath hot water temperature and the amount of hot water in the bathtub are detected continuously or periodically, and based on these detected values, the rotation speed and the feed water flow rate of the compressors 7a and 7b are controlled in step S147. . Then, as in FIG. 6, in steps S149 and S151, the bath hot water temperature, the hot water temperature and the amount of hot water in the bathtub 65 are determined, and if within the set value range, the process proceeds to step S153 to stop the bath chase operation. To do.

  As described above, the hot water storage amount is reduced and the hot water storage temperature is lowered by setting the hot water storage amount of the hot water storage tank 21 to be appropriately variable according to external conditions such as the outside air temperature and the water supply temperature. As a result, heat loss from the hot water storage tank can be reduced and energy can be saved.

  In addition, by providing two hot water supply circuits, tank hot water supply and direct hot water supply, there are a total of three types of hot water supply circuits, that is, a single circuit and two-circuit simultaneous operation, thereby making it possible to diversify the use of water heaters. That is, normally, an energy-saving operation of only a direct hot water supply operation is performed, and when there is a large amount of hot water supply in winter or when using a shower, the direct hot water supply circuit and the tank hot water supply circuit can be used at the same time. Therefore, a small capacity hot water storage tank can have a large function.

  In addition, in order to directly supply hot water, the entire heat pump cycle has to have a large capacity, and there are many problems. It can be used as it is, and even if one unit breaks down, the remaining circuit can make up for hot water supply.

  In this embodiment, there is a great effect in the direct hot water supply method using the hot water in the hot water storage tank immediately after the start of the heat pump operation, but also in the conventional tank hot water method in which the hot water stored in the hot water storage tank covers all the hot water supply. Needless to say, similar effects can be obtained.

It is a block diagram which shows an example of the heat pump hot-water supply apparatus to which this invention is applied. It is a schematic diagram which shows an example of the water-refrigerant heat exchanger of FIG. It is an example of the bath heat exchanger of FIG. 1, (a) shows sectional drawing from a side surface, (b) shows sectional drawing from the front. It is a flowchart which shows the driving | operation operation | movement at the time of installation of the hot water supply apparatus which concerns on this embodiment. It is a flowchart which shows the operation | movement at the time of the hot water supply of the hot water supply apparatus which concerns on this embodiment. It is a flowchart which shows the hot water filling operation | movement in the bath automatic operation of the hot water supply apparatus which concerns on this embodiment. It is a flowchart which shows the operation | movement of the bath memorial in the bath automatic operation of the hot water supply apparatus which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat pump refrigerant circuit 3 Hot water supply circuit 5 Operation control means 15 Water-refrigerant heat exchanger 21 Hot water storage tank 23 Tank circulation pump 41 Water supply port 57 Hot water supply port 75 Bath heat exchanger

Claims (6)

A heat pump for heating the hot water; a hot water storage tank for storing hot water heated by the heat pump; a first hot water supply pipe communicating with the hot water outlet of the heat pump and the top of the hot water storage tank; More than the set temperature of the hot water tank, a second hot water pipe communicating with the mouth, a water supply pipe communicating with the water source and the bottom of the hot water tank, a water supply pump supplying water to the heat pump from the bottom of the hot water tank A heat pump comprising a hot water amount adjusting means for detecting the amount of hot water and adjusting the hot water amount to be equal to or higher than a predetermined amount by operating the heat pump and the water supply pump when the detected value is less than a set amount. Hot water supply device. The heat pump hot water supply apparatus according to claim 1, wherein the first and second hot water supply pipes are communicated with each other. A heat pump for heating the hot water, a hot water storage tank for storing hot water heated by the heat pump, a first hot water supply pipe communicating with the hot water outlet of the heat pump and the top of the hot water storage tank, and the first hot water supply pipe, A second hot water pipe communicating with the hot water outlet, a water pipe communicating between the water source and the bottom of the hot water tank, a water pump for supplying water to the heat pump from the bottom of the hot water tank, and a set temperature of the hot water tank Hot water amount adjusting means for detecting the amount of hot water as described above and operating the heat pump and the feed water pump to adjust the hot water amount to be equal to or greater than a set amount when the detected value is less than the set amount; A heat pump hot water supply apparatus comprising: control means for detecting the release of the heat pump, starting the heat pump, and starting water supply to the heat pump after the heating capacity of the heat pump is stabilized. The hot water amount adjusting means detects at least one of an outside air temperature and a feed water temperature, and variably sets the set amount based on the detected temperature. Heat pump water heater. The hot water tank is formed by attaching a plurality of temperature sensors in the height direction of the hot water tank and detecting a hot water amount equal to or higher than the set temperature based on a detected temperature detected directly or indirectly by the temperature sensor. The heat pump hot-water supply apparatus in any one of 1-4. The heat pump hot water supply apparatus according to any one of claims 1 to 5, wherein a plurality of the heat pumps are provided in parallel.

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